The present invention relates to an apparatus for measuring the thickness of materials using the focal length of a lensed fiber and a method thereof. More particularly, the invention relates to a method of measuring the thickness of materials using the strength of the beam reflected from the focal length when the beam emitted from a lensed fiber is focused on a material.
So far, many methods have been available for measuring the thickness of materials such as measuring the thickness of materials based on the analysis of interference patterns or using the height differences of materials after an etching process.
Measuring the thickness of materials based on the analysis of interference patterns is very sensitive to the external factors, thereby requiring a very stable environment in order to conduct a proper experiment. Also, the collected results should be analyzed by a suitable computer making the process unnecessarily complicated.
Measuring the thickness of materials based on an etching process is mainly used for semiconductor fabrication process. However, the process is very complex and requires highly toxic chemicals.
The present invention is designed to overcome the above problems of prior art. The object of the invention is to provide an apparatus for and method of measuring the thickness of materials using the focal length of a lensed fiber using the fact that the reflected beam from the focal length is the strongest when the beam emitted from a lensed fiber is focused on the materials.
In order to achieve the above object, the present invention provides a method of measuring the thickness of materials using the focal length of a lensed fiber through analyzing the quantity of the beam reflected from a substrate which was emitted from the end of a lensed fiber during a vertical movement of the lensed fiber. The lensed fiber here is attached to a Piezo Electric Transducer (PZT) in order to generate a Gaussian Beam (GB) and to focus the beam to a coated material on the substrate.